Move paint code from RenderHTMLCanvas to HTMLCanvasPainter.

Source/core/paint/HTMLCanvasPainter.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef HTMLCanvasPainter_h
+#define HTMLCanvasPainter_h
+
+namespace blink {
+
+struct PaintInfo;
+class LayoutPoint;
+class RenderHTMLCanvas;
+
+class HTMLCanvasPainter {
+public:
+    HTMLCanvasPainter(RenderHTMLCanvas& renderHTMLCanvas) : m_renderHTMLCanvas(renderHTMLCanvas) { }
+    void paintReplaced(PaintInfo&, const LayoutPoint&);
+
+private:
+    RenderHTMLCanvas& m_renderHTMLCanvas;
+};
+
+} // namespace blink
+
+#endif // HTMLCanvasPainter_h